Séminaire d'Abdallah Zaki, California Institute of Technology

À la uneÉvénement passé

Seminar at 4pm online

28 septembre 2023

Ancient water-formed landscapes and past climates on Earth and Mars

Our planet's arid landscapes frequently display spectacular fossilized landforms from greener times, such as ancient depositional rivers and traces of perennial lakes, which host important repositories of pre-existing surface processes. These features can be used to understand past environmental conditions responsible for sculpting the surfaces of both Earth and Mars. However, understanding how frequent, how sustained, and under what hydroclimatic regimes these systems survived is hindered by the lack of field observations and laboratory analyses that can help place quantitative constraints on their formative rates and preservation through time. Addressing these fundamental questions may improve our understanding of paleo-climates and aid in the hunt for ancient habitability on Earth and Mars. In this talk, I will show multiple related efforts that utilize field observation, remote sensing, geochronological techniques, and climate models to constrain the timing, duration, and hydroclimate of fossil rivers and lakes in compelling geological sites, including the Sahara, Arabia, and Mars. I will discuss the results obtained in light of their implications for past terrestrial and Martian climates, as well as the possible impact on habitability over space and time.


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